In a large bowl, combine the boneless skinless chicken thighs with vegetable oil and salt. Toss well to ensure every piece is coated. Let the chicken marinate for 10 minutes.

Once marinated, sprinkle cornstarch over the chicken pieces. Toss the chicken in the cornstarch until each piece is fully coated.

Preheat your air fryer to 450°F (230°C). Place the coated chicken pieces in the air fryer basket in a single layer, lightly spray them with oil and cook for 8 minutes. Flip the chicken and cook for an additional 5-6 minutes.

While the chicken is air frying, mix together the ketchup, Shaoxing wine, rice vinegar, light soy sauce, brown sugar, and water in a small bowl.

In a skillet over medium heat, add peanut oil and sauté minced garlic and ginger until fragrant. Add chopped white onion and bell pepper, cooking until they soften slightly.

Pour the prepared sauce into the skillet, stirring constantly until it thickens. Add the air-fried chicken to the skillet, tossing to coat evenly.

Transfer your Air Fryer Sweet and Sour Chicken onto a serving plate and serve immediately.